A Case Of Emmetropization Following Acanthamoeba Keratitis

To describe a case of corneal flattening and emmetropization of a -2.25 diopters refractive error due to corneal scarring following acanthamoeba keratitis.

Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland.

This is a report of a case that was treated for an acanthamoeba keratitis with hourly drops of Polyhexamethylene Biguanide 0.02% and Hexamidine 1mg/ml (Desomedine, Bausch & Lombm Switzerland), tapered over the course of 7 weeks. Moxifloxacine drops (Vigamox, Novartis, Switzerland) and artificial tears (Lacrycon, Thea, France) were also used 6 times per day. A treatment with Dexamethasone 0.1% drops (Dexafree, Thea, France) was also introduced the 6^th week of treatment. Autorefractometry was performed at each visit using the Tonoref^TM III (Nidek, Japan). Anterior segment imaging was performed using Anterion (Heidelberg Engineering GmBH, Germany) and included source OCT imaging, corneal tomography and epithelial thickness evaluation.

A 40-year-old female patient with a refractive correction of -2.25sph -0.50cyl at 180° in both eyes was treated for a contact-lens related acanthamoeba keratitis of her right 1 day following presentation. Spectacle corrected visual acuity was 1.0 decimal from the 3^rd to 5^th week. On the 6^th week, visual acuity was 1.0 decimal without correction and there was no measurable refractive error. A newly formed stromal scar of 0.5mm in the central part of the cornea was responsible for a corneal flattening and epithelial thickening inferiorly. Topical corticosteroid treatment t.i.d was initiated and gradually tapered over the course of 8 weeks with partial reversal of the corneal flattening and regularization of corneal epithelium.

Cornea stromal scarring can be observed in cases of acanthamoeba keratitis with isolated epithelial involvement even when the treatment is initiated without delay. In this case, corneal scarring led to flattening of the cornea and emmetropization of one eye of the patient. This led to a notable anisometropia and spectacle intolerance, although monocular visual acuity was normal. Close follow-up of cases of infectious keratitis with refraction and corneal imaging allows early detection of such anomalies. Treatment with lubrication and corticosteroid drops can potentially reverse changes in corneal curvature and should be considered in such cases.